Gas turbine engines, such as those utilized on commercial aircraft, include a compressor operable to compress air, a combustor that mixes the compressed air with a fuel and ignites the mixture, and a turbine section that is driven to rotate by expansion of the resultant combustion gasses. The compressor, combustor and turbine are contained within an engine core. In some engines a fan is mounted at the front of the engine core. The rotation of the fan is driven by the turbine. In some gas turbine engines, referred to as turbofan engines, the fan drives air into the compressor and into a fan duct surrounding the engine core.
In order to properly heat and cool the various engine systems and components within the cowl and the engine core, a liquid coolant is pumped through the engine, and through multiple heat exchangers in a thermal management system. Existing thermal management systems typically dispose at least a portion of the heat exchangers in the fan duct in a manner that creates drag on the air passing through the fan duct. The creation of drag on the air passing through the fan duct decreases the efficiency of the engine.